SBI3U Unit 3 Review

Artificial Selection

100

Define artificial selection.

Individuals with desired traits are selected as parents of next generation

200

Name on technology that could be used with artificial selection.

Genetic engineering or cloning

300

How can artificial selection affect genetic diversity?

Reduces gene pool/variety of genes

400

Describe the two limitations of artificial selection discussed in class.

Relies on the presence of a gene

Undesirable traits may accompany desired traits

500

List the steps of an artificial selection experiment.

Pick a useful species

Breed a large number

Pick a trait of interest

Identify individuals with trait of interest

Breed individuals with trait of interest

Repeat the previous two steps

Adaptation and Fossil Formation

100

What were Lamarck's principles?

Use and disuse

Inheritance of acquired characteristics

200

How does the field of epigenetics describe how environmental factors affect traits without changing genes?

Molecular switches turn genes on and off based on factors that individual is exposed to.

300

What are the two ways that fossils could be formed?

Permineralization and carbonization

400

How can catastrophism be more accurate than uniformatirianism?

Fossils need harsh conditions to form which are provided during catastrophes

500

Someone claims that very ancient organisms were very likely to be a lot more complicated than current organisms. Describe how fossils can disapprove this statement.

Fossil complexity decreases as you dig deeper into the ground

Math Stuff

100

How much mass would a 10 kg radioactive substance have after 2 half lives?

2.5 kg

200

What is the Hardy-Weinberg equilibrium equation?

p²+2pq+q²=1

300

What is the half-life equation? Describe what each variable represents.

M = M₀(0.5)ⁿ

400

A radioactive substance starts out with 500 grams. After 16 years, it is found to have 31.25 grams. How long is one half-life for this substance?

4 years

500

The allele B represents black fur in mice and is dominant. The allele b represents white fur and is recessive. If 12% of mice population are white, what are the genotype frequencies of bb, BB, and Bb?

q² = 0.12

2pq = 0.455

p² = 0.4225

Speciation and Patterns of Evolution

100

Define speciation

The formation of new species from an existing species

200

List and distinguish between the three types of natural selection

Directional: One extreme

Stabilizing: Neither of the extremes (middle or average)

Disruptive: Both extremes

300

How did the Galapagos Finches exhibit speciation. Explain your answer.

One species likely migrated and competition within that species forced the development of new features that led to new species

400

A group of paleontologists are searching for fossils and suddenly find a large number of dinosaur fossils. No dinosaur fossils were found up until that point. As they dig deeper, they still kept finding dinosaur fossils but in significantly lower numbers. Explain the pattern of evolution that is being observed here and how does it justify the numbers of fossils as you dig deeper.

Dinosaurs used to live and rare extreme conditions would fossilize dead dinosaurs. Extinction caused extreme conditions over a massive scale, creating several fossils. Since dinosaurs became extinct due to a catastrophic event, no more fossils could be found closer to the surface of Earth.

500

Two similar looking birds (one male and one female) are being observed by scientists. No mating is taking place between them during mating season. They also notice that the female bird is annoyed by the sounds that the male bird is making. List the type of speciation, mechanism (prezygotic or postzygotic), and type of isolation. Explain your choice for each pick.

Sympatric speciation (within same habitat), prezygotic (no mating takes place), and behavioral isolation (sound prevents mating)